'Grayest Generation': Older Parenthood In The U.S.

Judith Shulevitz, the science editor at The New Republic, wrote most recently for the magazine about older parenthood in the United States.

Judith Shulevitz

In a December article for The New Republic, "The Grayest Generation: How Older Parenthood Will Upend American Society," the magazine's science editor Judith Shulevitz points out how the growing trend toward later parenthood since 1970 coincides with a rise in neurocognitive and developmental disorders among children.

Drawing on research published in Nature, Shulevitz writes that, while the associations between parental age and birth defects were largely speculative until this year, "when researchers in Iceland, using radically more powerful ways of looking at genomes, established that men pass on more de novo — that is, noninherited and spontaneously occurring — genetic mutations to their children as they get older. ... [T]hey concluded that the number of genetic mutations that can be acquired from a father increases by two every year of his life, and doubles every 16, so that a 36-year-old man is twice as likely as a 20-year-old to bequeath de novo mutations to his children."

By proving that it's not simply the mother's age and health that affects the fetus, Shulevitz says the dynamic surrounding discussions of fertility will change. "No longer need women feel solely guilty," she tells Fresh Air's Terry Gross. "They can point to their husbands — and perhaps that's not really a nice way of putting it — but it means that the problem is shared by both sexes."

There is also some research that indicates fertility treatments taken by women of advanced maternal age could contribute to developmental delays. Shulevitz herself took the fertility drug Clomid. She had her first child when she was 39 and her husband was in his mid-40s, and says she began looking into the connections among fertility treatments, parental age and children's health while taking her son — who had a minor case of sensory integration disorder — to occupational therapy. As she'd sit and wait for him, she'd watch a parade of older mothers with children who had much more serious disorders than her son's.

This doesn't mean Shulevitz is a proponent of rushing parenthood. She acknowledges that there are "very powerful social forces at work on women that make it hard for them to even imagine having babies before their early to mid-30s."

"The thing I want people to take away from this article," she says "is that we're not studying [fertility] enough. We don't regulate it enough. ... [W]e celebrate triumphantly each breakthrough as if it was an absolute good, and we don't go cautiously enough and I think that's a problem, and as the age of first birth creeps up more, and more women are going to be availing themselves of these technologies, and I think that we really ought to go carefully."

Interview Highlights

On why she decided to use Clomid and the guilt she carries that it may have contributed to her son's development

"The doctor said, 'You know what ... you're 38. You're going to have a hard time getting pregnant anyway. Let's just throw Clomid into the mix and speed this process along,' because this was a decade ago, and it was before a lot of these concerns about endocrine disruptors and hormones and patterns of gene expression and patterns of fetal development had been raised, and everyone thought it was really safe, and I now blame myself for having this cavalier attitude toward taking drugs before, you know, hatching a baby in my womb. Do I know for a fact that [Clomid] has anything whatsoever to do with [my son's] condition? No. It could easily be genetic. I have appalling handwriting, and one of his problems is fine control — you know, holding a pencil, or was — so who the heck knows. He could have just gotten that straight from me."

On how the issue of fertility is one that affects not just elite women

"I've been accused of kind of having a class bias in this article, of only focusing on the problems of elite women, and I think that's fair to some degree. I perhaps didn't make it clear enough that what I think is the problem is that if you want to pursue the American dream and move out of poverty into the middle class, which requires you to pursue a career or a profession, you are hard-pressed to have your children in your 20s. ... It's a problem of women who want to work in the professions, who want to build an actual career for themselves rather than go from job to job or get mommy-tracked, but I don't think that's just a problem of the elite. I think it's a problem for everyone because it limits social mobility and it limits the choices women have. I don't want women to feel like they have to have children in their 20s, but I've talked to some women who wish they had, and they felt that they didn't have the choice to."

On why she ended up marrying and having children late

"I honestly sort of forgot to get married. I just sort of forgot. I, like, woke up in my early 30s and thought, 'Gee, I kind of forgot to get married here.' I didn't meet a man I wanted to marry till I was 34 — that's my current husband — and we didn't actually marry till I was 36, and I started worrying about our ability to have children when I was 37. And I've talked to a lot of women like that who say, 'Look, I didn't meet the guy I wanted to marry till I was in my mid-30s, so that's when I was able to start having children and start a family. To which I say, you know, 'great.' Once you've met the person you want to marry, you can't imagine doing it any other way, of course, and I don't mean to criticize you for having done it that way. It was what it was. But I think that I wasn't thinking about it. I wasn't taking my relationships all that seriously because no one around me was. I was a journalist, and it was expected that I put in these crazy hours and devote myself entirely to my career, and I was perfectly inclined to do that and everyone around me was doing that, so it just didn't occur to me to think about it. Maybe the reason I met the guy I wanted to marry when I was 34 was because I was ready to start thinking about getting married.

"There's a kind of either-or here. There's an either you become a respected journalist by working your head off, or you go and start a family, and what I'm saying is we have to start thinking about combining those two, because I found myself in a situation where I worried that my advanced maternal age was endangering my children and even threatening my chances of having any, which is what drove me to the fertility doctor. ... If it had been something other people were doing, I might have started to think about it, and if it had been something that my bosses would have thought was fine, then I might have started to think about it. I mean my bosses — who are part of the same system — would have looked askance. They would have said, 'Well, she's not serious.' "

On wanting to live to see and get to know her grandchildren

"My son said to me recently — he's 10 now — and said to me, 'So, let's see, you were 39 when I was born, so if I wait to 39 or 40 to have my first child, you will be almost 80. What kind of grandmother are you going to be?' And, you know, I had nothing to say to that. I mean, hopefully, a living one. ... I don't want to be too old to be a presence in my grandchildren's lives. ... I think it's really important to have the generations communicating among one another and to have family traditions and history being passed along and for parents to have that kind of familial support that grandparents can offer."

On how she reconciles the large roles that both science and religion play in her life

"What we're discovering is that we're enormously malleable. We're really responsive to our environment, and not just to our environment in a physical sense but also in a psychological sense, in the sense that stress is one of the really big forces in epigenetic changes. So the malleability of the human body seems to me an argument for creating a better community, a better society, and that's what I love about religion, is that it's a place where you can turn for ideas about the good society. I recognize — as many people go around arguing — that religion can be used as a force for bad — as any set of ideas or ideology can be — but it can also be used as a source of ideas that drive us to the greater good. So I turn to science to tell us how to live, and I turn to religion to tell us how to live, and I follow neither of them slavishly."

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Transcript

TERRY GROSS, HOST:

This is FRESH AIR. I'm Terry Gross. Older parenthood is becoming more common and my guest, Judith Shulevitz, is part of that trend. She had her first baby when she was in her late 30s and her husband was in his mid-40s. Their child was diagnosed with a minor neurodevelopment disorder which led her to wonder: Did her age or her fertility treatments have anything to do with that?

Shulevitz is the science editor of the New Republic so she examined the research and wrote an article for the magazine, which was published last month, titled "The Grayest Generation." Her article also tells her story and addresses some of the issues faced by older parents.

Judith Shulevitz, welcome back to FRESH AIR. You know, you're one of the parents in the group that you're writing about. You became a parent when you were how old?

JUDITH SHULEVITZ: Thirty-nine.

GROSS: And you write: We don't know - we meaning older parents - we don't know what we're getting ourselves into. What are some of the concerns you had as an older parent seeing your own experiences, seeing the experiences of older parents that you know? What were some of the concerns you had that you wanted to address through your research?

SHULEVITZ: Well, I tell the story in the article about taking my son - who was born when I was 39 - to an occupational therapy gym. And he had a very minor case of something called sensory integration disorder, which was, you know, addressed and really isn't much of an issue anymore.

But I sat on these little chairs - they always put out little chairs at these gyms; I've been to a couple now - and I watched a parade of older mothers come through with children with much more serious disorders than my son's. And it began to sort of percolate in my brain that maybe there was an issue here, that maybe the rise, the much-noted rise, of various neurocognitive and developmental disorders wasn't simply the expansion of the diagnostic apparatus or our heightened awareness of these issues, but was really possibly linked to the fact that we are having children much older. So I began to wonder and I wanted to answer that question.

GROSS: So had many of the women you were seeing at the occupational therapy gym whose children had neurocognitive or developmental disorders, had many of them used fertility treatments?

SHULEVITZ: You know, I don't know. That came from my friends because that's the kind of information you don't casually ask a fellow mother who's sitting, you know, next to you in the waiting room of one of these gyms.

GROSS: Good point.

SHULEVITZ: Yeah. But I belong to a cohort of journalists and, you know, my various relatives who are professionals, and I just started hearing a lot of stories about people who had had fertility treatments and had children with obsessive compulsive disorder, Aspergers, autism, ADHD. And again, you know, it didn't really occur to me that there was much of a link until I began to read about the fertility industry.

And I realized that we just don't know what we're doing. There just isn't a lot of data, particularly in America. The good stuff is coming out of other countries where they actually have the information collated in a national health registry. In this country the fertility industry only reports pregnancy rates to the CDC - the Centers for Disease Control - and we don't do follow-up studies.

So I just wondered if there was a link and what was known about it. I didn't surmise so much that there was one. I wanted to be told that there wasn't. And the more I asked, the more it seemed like there was.

GROSS: So after doing some research investigating what science has to say about whether there's any correlation between using certain in vitro fertilization techniques and giving birth to a child who has developmental or cognitive disorders, what kind of statistics did you find?

SHULEVITZ: So the study I came across that was most convincing to me was an article in the New England Journal of Medicine, and it came out last May. And it found that 8.3 percent of children born with the help of assisted reproductive technology had defects. Whereas of those born without it only 5.8 percent did.

And I thought that was a pretty big figure. And as I looked at the study more closely I discovered that certain procedures were more closely correlated to defects than others. So for example, in vitro fertilization wasn't that highly correlated with birth defects, but Clomid, which is a very common drug taken by women just starting fertility treatment, was.

And another procedure that involves injecting sperm directly into the egg, and which is often done with IVF, also was. And, you know, one reason for that might be that the egg has natural ways of rejecting sperm that are defective or shouldn't be used to impregnate the egg. And those were being bypassed.

As for the Clomid, one suspicion that the author of that article had is that it produces hormonal changes in the body and could even build up in the body so that those hormonal changes are still happening even as the baby is developing. Which is not a good scenario for the baby.

It had previously been thought that it just washes out of the body. And another reason he thought Clomid could be dangerous is that it's increasingly available over the Internet and people are taking it without the supervision of doctors. It's so common people don't see that it could be dangerous, and he thinks that could have really bad outcomes.

GROSS: So if the Clomid stays in a woman's body as she is pregnant, how would that affect the development of the fetus? What is the concern there?

SHULEVITZ: Well, let me stress that it's a concern and it hasn't been proven. The mechanism whereby this happens hasn't been proven. But what we are finding is that very small, subtle changes in the hormonal balance of the body can alter fetal development, and in permanent ways.

Because what's happening as a baby is unfurling in the womb, its brain architecture, its fundamental body structure, is being shaped and being shaped for life. So increasingly we're becoming aware of the fact that chemicals building up in the body can have lasting effects on the lifelong health of the fetus.

GROSS: Now, you used Clomid.

SHULEVITZ: I did use Clomid.

GROSS: And so do you have this whole thing going on in your mind of, like, guilt that your son's mild cognitive disorder might be a result of the Clomid which apparently you needed in order to conceive him in the first place? I mean, it's - do you get trapped in that cycle of thinking about it?

SHULEVITZ: I do. I do. And I'll tell you why. I didn't really need the Clomid. I had a very minor condition which kept me from getting pregnant. It was surgically corrected. But the doctor said, you know what? You're 30 - I think I was 38 by then - you're 38. You're going to have a hard time getting pregnant anyway. Let's just throw the Clomid into the mix and speed this process along.

Because, you know, this was a decade ago and it was before a lot of these concerns about endocrine disrupters and hormones and patterns of gene expression and patterns of fetal development had been raised. And everyone thought it was really safe. And I now blame myself for having this cavalier attitude toward taking drugs before, you know, hatching a baby in my womb.

Do I know for a fact that it has anything whatsoever to do with his condition? No. It could easily be genetic. I have appalling handwriting and one of his problems is fine motor control, you know, holding a pencil - or was. So who the heck knows? He could've just gotten that straight from me.

GROSS: So are you concerned that your article is going to make a lot of mothers feel guilty?

SHULEVITZ: Well, I try really hard in the article - and sometimes I think I didn't try hard enough - but I do try to make it clear that what we're talking about are these very powerful worldwide trends throughout developed - and, to my surprise, developing nations - toward the delay of the age of first birth.

So I think there are very powerful social forces at work on women that make it hard for them to even imagine having babies before their early to mid-30s. So I want to make it clear that I think there are structural reasons, and that women are simply following social norms rather than making individual bad choices.

GROSS: So just to clarify, in terms of there being a correlation between certain fertility treatments and children being born who have or develop cognitive or developmental disorders, we're talking about statistics and studies that point to certain patterns. But we don't have as far as I know definitive evidence of cause and effect between the fertilization techniques and the drugs being used and developmental disorders.

SHULEVITZ: No, we don't. I mean I think that there are some very suggestive evidence in animal studies, but it's a heck of a lot harder to do on, you know, human women. But the thing I want people to take away from this article is that we're not studying it enough, we don't regulate it enough. We celebrate triumphantly each breakthrough as if it was an absolute good, and we don't go cautiously enough, and I think that's a problem. And as the age of first birth creeps up, more and more women are going to be availing themselves of these technologies and I think that we really ought to go carefully.

GROSS: So it's the clinics that aren't doing the follow-up research on how the fertility drugs may or may not affect the development of the baby?

SHULEVITZ: Well, I don't know if I would fault the clinics. I would fault the government. What the government does is collect data from the clinics on how many women get pregnant. So what they're looking at is the efficacy of these treatments. But they're not looking at what happens. Nobody is officially required to report on what happens to the children who are born of these treatments. And that bothers me because, you know, we just don't know and we should be finding out.

GROSS: So the government does require fertility treatment centers to come up with data about the rate of fertility after the treatments?

SHULEVITZ: Yes. They do. About the rate of pregnancy. Yes, they do. And I suppose, I haven't looked into what exactly it is, but I suppose that if you miscarry, that probably doesn't count as a successful outcome. But - and I don't even know if fertility clinics should be required to do follow-up studies. Is that their job or should there be someone else who is doing that? So one of the things that I found is that some of the best data on this stuff is coming from countries that have a national health care because what they have is a bureaucracy, which collects data on everything, right? They collect data on who's getting fertility treatments and then they have data on the children of those fertility treatments. And so scientists can come along and study that data. We don't have - all of this is privatized and fragmented, so we don't have an easy way of studying what's happening in the States. So the breakthroughs in this stuff are coming from Scandinavia and Australia and other places like that.

GROSS: If you're just joining us, my guest is Judith Shulevitz. She writes about science for The New Republic. We're talking about a recent article called "The Grayest Generation," about how many people are having children at an older age. And the article investigates whether being older and whether certain fertility treatments can increase the likelihood of giving birth to a child that has cognitive or developmental disorders.

Let's take a short break here, and then we'll talk some more. This is FRESH AIR.

(SOUNDBITE OF MUSIC)

GROSS: If you're just joining us, my guest is Judith Shulevitz. And we're talking about her recent article in The New Republic, where she writes about science. The article is called "The Grayest Generation," and it's about people who are having children at an older age. And the article asks, first of all, why is that happening? Why are people delaying parenthood? But also, does giving birth at an older age, you know, carrying a child at an older age, increase the likelihood that the child will have developmental or cognitive disorders? And does the use of certain fertility treatments also increase the likelihood of having a child with developmental or cognitive disorders?

You know, we were talking about fertility techniques. Let's look about just age itself. As a woman gets older, is there a correlation between age and giving birth to a child who has developmental disorders?

SHULEVITZ: Oh, yes. As a woman gets older, there a greater likelihood that she will have something called a trisomy, which is a condition in which an extra chromosome inserts itself into her set of chromosomes, into one of the pairs. And there are several famous trisomies, like Down syndrome. And there are others which are more benign, but there is no question that Down syndrome, for example, and some of the others are linked to older age - or as they call it on the medical charts, advanced maternal age. And she is much more likely to have multiple children, which actually is correlated to poor health outcomes, to have children that are born at low birth weights. Again, not good for the child. And to spontaneously abort.

But one of the things that fascinated me was that as women grow older before they have children, so do their husbands or partners and at a very steady rate; they're about three years older on the average than the women they have children with. And that as they age, they too are at a greater risk of producing a child with a neurocognitive or developmental disorder. And that's one of the new findings, it's one of the startling findings, and it also, I think, really changes the dynamic of this discussion because no longer need women feel solely guilty. They can point to their husbands and perhaps that's not really a nice way of putting it, but it means that the problem is shared by both sexes, and I think that's going to change the way we think about it and make it easier to address.

GROSS: Well, what are the risks to a man's sperm as he grows older?

SHULEVITZ: Well, the basic risk is that he will have more what are called to de novo mutations or spontaneous non-inherited mutations, which increase at a rate of about two a year and double every 16 years, and that those mutations could lead to health problems - and not just necessarily neurocognitive ones, although there are some really interesting research on that, but you know, cardiovascular ones and long-term lifelong health problems.

GROSS: And do any of these changes in a man's sperm as he ages have anything to do with toxins that the man has ingested over time? And by toxins I mean just like stuff in the air that we all breathe...

SHULEVITZ: Right.

GROSS: ...that we know, you know...

SHULEVITZ: Right.

GROSS: ...the air is filled - there's toxins in the air. There's toxins in certain foods. There's toxins in certain plastics. You know, I could go on.

SHULEVITZ: Right. Exactly. So this takes us into the realm of epigenetics, which is a fairly new sub-discipline of genetics. And it studies not genes per se, but how genes are expressed, and as they are expressed, how they govern the activity of those genes, the protein making activity of those genes, and how they can change all kinds of parts of the body, including sperm. So as toxins build up in your body, it can change the epigenetic patterns in your body and it can alter sperm. There's a very clear link between environmental toxins and sperm. So that's pretty worrisome. So the older a man is, the more time he's had to take all the stuff into his body. And there's all kinds of studies correlating smoking and obesity in children, smoking by the father and obesity in children, or poor nutrition of the father and various problems in the children, metabolic disorders in the children. So that's another way that a man can potentially court danger as he ages.

GROSS: Yeah, this is interesting because pregnant women are told, you know, don't smoke. Don't drink. Be careful what you eat. And the burden is always on the woman and she is the one carrying the child. But apparently a man can pass on problems too - according to new research, if he's been exposed to toxins.

SHULEVITZ: Right. So, you know, we think we're the ones carrying the children; we're the ones shaping the environment, so it makes perfect sense that we have the most to do with it. And it may be true that we do because what happens in the womb is very important for how a child turns out. But it is increasingly looking like sperm has a very important role to play in directing fetal development. So you know, the older a man is, the more risk there is that there are problems in his sperm.

GROSS: So we're talking about risks related to childbearing later in life. And there are reasons why a lot of people are having children later in life. And you know, those reasons are kind of obvious. But I'm going to ask you to run through some of them anyway, because it's indicative of, you know, larger trends in our culture. And it's also, I think, a result of feminism.

SHULEVITZ: Right. I mean I would never want to be in a position of saying that there's anything wrong with women taking control of their own fertility, which is one of the great triumphs of feminism, and also the advent of birth control. So the advent of birth control has made it possible for women to decide when they're going to have children. And I think that is absolutely a good thing. But I think that what has happened as a result of that is that we have developed social norms which say women who want to have a career had better delay having children because they've got to get really serious about their career in their 20s and early 30s, before they have children. There's all kinds of studies that show that the earlier you have your child, if you're working in a profession or trying to build a career, the lower your lifetime earnings will be, which means that the earlier you have a child - well, it means that if you have a child there's a high opportunity cost. And I think there are these social norms that have arisen that we all respond to.

GROSS: Judith Shulevitz will be back in the second half of the show. Her article "The Grayest Generation" was published last month in The New Republic, where she's the science editor. You'll find a link to her article on our website FRESH AIR.npr.org.

I'm Terry Gross and this is FRESH AIR.

(SOUNDBITE OF MUSIC)

GROSS: This is FRESH AIR. I'm Terry Gross back with Judith Shulevitz. We're talking about the trend of women and men having children later in life. She's an example. She was in her late 30s, her husband in his mid-40s, when they had their first child. Shulevitz is the science editor of The New Republic. And last month, in her article "The Grayest Generation," she reported on research into whether age or fertility treatment adds to the chances of having a child with a developmental disorder. She also wrote about how this trend of older parents is affecting life within individual families as well as the larger society.

In some ways it seems like, you know, America is heading in two directions at the same time because on the one hand you have a lot of parents who are becoming first-time parents at around the age of 40, and at the same time you have a lot of people becoming parents in their teens or even in their early teens. And there's an interesting demographic quote about that, about the difference between those two sets of people.

SHULEVITZ: Yeah. So in the article I point out that overall fertility rates are going down in this country, among teenagers as well as among women in their 20s, and even in their 30s, and that's happened since the recession - the beginning of the recession in 2008. The only category that's either going up or staying the same is for different categories of women over 40 - 40 to 45, I guess 40 to 44, 45 to 49 and so on. But what you're pointing at is really a distinction - a class distinction in this country between poor and immigrant women and women who are in the middle class, trying to move into the middle class, or in the upper middle classes.

And so I've been accused having kind of a class bias in this article, of only focusing on the problems of elite women, and I think that's fair to some degree. I perhaps didn't make it clear enough that what I think is the problem is that if you want to pursue the American dream and move out of poverty into the middle class, which requires you to pursue a career or a profession, you are hard-pressed to have your children in your 20s.

GROSS: Because that's going to hold you back from the education or the career opportunities...

SHULEVITZ: That's right.

GROSS: ...or staying up super late, which you might be expected to do, getting in super early.

SHULEVITZ: Right. I mean when you're getting an education, if you're getting a graduate degree, the hurdles are very high, the work is very intense. The child care at universities tends not to be great. The expectation is you're not going to show up in a law school class carrying a baby, you know, or you know, rushing home from the library to take care of your child. And indeed, it's very hard to combine those two things. If you are an associate at a law firm and you want to make partner, you have to work like a dog into your early 30s or mid-30s and people do put off having children till they've made partner, gotten tenure, passed through their medical residency, or simply gotten the promotion to put them into the managerial position that gives them a little more freedom to control their own schedule.

So I think that, yes, it's a problem of women who want to work in the professions, who want to build an actual career for themselves rather than go from job to job or get mommy-tracked, but I don't think that's just a problem of the elite. I think it's a problem for everyone because it limits social mobility and it limits the choices women have. I don't want women to feel that they have to have children in their 20s, but I've talked to some women who wish they had, and they felt that they didn't have the choice to.

GROSS: So you point out in your piece that some countries are starting to create policies that will enable women to have children at an earlier age if they so desire and not penalize them professionally for doing it. What are some of those policies?

SHULEVITZ: So there a large number of countries in the industrialized world where the - what's called the replacement rate, or the number of children being born to replace the number of people dying is below two per couple. So that means that the population growth is going down in those countries and the population could be going down in those countries, and countries are worried about that because then they become top-heavy. They have to worry about an aging population and about there being fewer people in the workforce to generate the wealth that could help take care of them. So they've put in place what are called pro-natalist policies, which range from direct subsidies to women who have children to very generous tax credits, to on the other end, things like universal and affordable child care, day care, and guaranteed paid parental leaves, which is to say in some countries paternal leave as well as maternal leave. And these have been shown to bring down the age at which women first start having children.

GROSS: What do you think the odds are of the United States ever having policies like that?

SHULEVITZ: I think at the moment they look pretty poor. But we are not below replacement rate and the reason we're not below replacement rate is the high rate of immigration, basically. We don't worry about our work force being diminished, even though we're moving into the age - the era in which baby boomers start retiring and we too are going to be having a top-heavy society. But we keep those numbers higher because we bring in immigrants, and also we - and some of those immigrants come from cultures where it's just expected that women will have children earlier. They haven't sort of adjusted to the American norms. So until you start to worry about that, you're not inclined to put those policies in place.

Now, there's also a political climate in this country that makes it hard to imagine, you know, any more money going out to anybody for any social service. So you know, I don't think it's - I don't think the prospect is great in this country but I think it's still time to start talking about it.

GROSS: Well, what are some of your reasons, if you don't mind my asking, for having children beginning when you were in your late 30s?

SHULEVITZ: So I honestly sort of forgot to get married. I just sort of forgot. I, like, woke up in my early 30s and thought, gee, I kind of forgot to get married here. I didn't meet a man I wanted to marry till I was 34 - that's my current husband - and we didn't actually marry till I was 36 and, you know, I started worrying about our ability to have children when I was 37. And I've talked to a lot of women like that who say, look, I didn't meet the guy I wanted to marry till I was in my mid-30s, so that's when I was able to start having children and start a family. To which I say, you know, great. Once you've met the person you want to marry, you can't imagine doing it any other way, of course, and I don't mean to criticize you for having done it that way. It was what it was. But I think that I wasn't thinking about it. I wasn't taking my relationships all that seriously because no one around me was. I was a journalist, and it was expected that I put in these crazy hours and devote myself entirely to my career, and I was perfectly inclined to do that and everyone around me was doing that, so it just didn't occur to me to think about it. Maybe the reason I met the guy I wanted to marry when I was 34 was because I was ready to start thinking about getting married.

GROSS: So, but you know, it worked for you in the sense that, you know, like you have two children now. You have a husband and you have a great career.

SHULEVITZ: Yeah. And I have a great life and my children benefit from the fact that I'm more mature. Imagining me being a mother at 20 is a little - or 25 or in my 20s - it's a little alarming to me because I was impulsive, immature and poor, so how was I going to support that child?

GROSS: And you wanted a career. I mean, right? I mean...

SHULEVITZ: Yeah.

GROSS: ...you wanted to become a journalist and to make it - to be good at it and respected enough to make an impact.

SHULEVITZ: That's right. I absolutely did. But, you know, there's a kind of either-or here. There's an either you become a respected journalist by working your head off, or you go and start a family, and what I'm saying is we have to start thinking about combining those two, because I found myself in a situation where I worried that my advanced maternal age was endangering my children and even threatening my chances of having any, which is what drove me to the fertility doctor. So you know, if it had been something that other people were doing, I might have started to think about it, and if it had been something that my bosses would have thought was fine, then I might have started to think about it. I mean my bosses - who are part of the same system - would have looked askance. They would have said, well, she's not serious.

GROSS: Now you have concerns about being an older mother and what that might mean for you and for your children a few years down the line. What are some of those concerns?

SHULEVITZ: Well, let's just put it this way, I take a lot of fish oil. I take a lot of vitamins and I exercise a lot because I want to be around. I want to be in good health and I want to be around. I mean everybody should do that, of course, but I worry about it.

My son said to me recently - he's 10 now - and said to me, so, let's see, you were 39 when I was born, so if I wait to 39 or 40 to have my first child, you will be almost 80. What kind of grandmother are you going to be? And, you know, I had nothing to say to that. I mean hopefully a living one.

But you know, I don't want to be too old to be a presence in my grandchildren's lives. I happen to actually to have just finished an article about grandparents who fascinate me, and it's really clear that they make a material difference in children's lives - not just financially, but that's also true - but psychologically. And I think they make a big difference to this culture. I think it's really important to have the generations communicating among one another and to have family traditions and history being passed along, and for parents to have that kind of familial support that grandparents can offer.

I mean it's not indispensable. Plenty of people grew up without grandparents throughout history. You survive, but I just - I don't think it's a social good.

GROSS: And you write about your concern for the children of older parents that, you know, the parents might require care of their own by the time this child is old enough to have children.

SHULEVITZ: Right.

GROSS: So instead of the grandparent being there for them, the grandparent is requiring care.

SHULEVITZ: Right. So dividing the parent's attention. So there's this term, the sandwich generation, which is when you're raising children and taking care of your parents at the same time. And I think the pressures on that sandwich generation could be increasing because the parents of the parents might need more intensive care, which could be emotionally or financially draining, and the children could be younger when that's happening, which also requires more intensive hands-on care. So I think that could be a problem. You know, I don't want my son to be in that situation. I think that's another thing he was asking about: Am I going to have to take care of you just as I'm having babies of my own? Am I going to have a toddler pulling on one hand and, you know, be on the phone with you in your old age home on the other? I don't want that.

GROSS: My guest is Judith Shulevitz. She writes about science for The New Republic. She'll be back after a break. Her article "The Grayest Generation" was published last month and we have a link to it on our website, @FRESH AIR. NPR.org. This is FRESH AIR.

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GROSS: If you're just joining us, my guest is Judith Shulevitz and she writes about science for The New Republic. And we've been talking about her piece "The Grayest Generation," about people having children at an older age and how age itself and also fertility treatments might affect the development of the children.

The last time you spoke, it was after the publication of your book about the Sabbath, the history of the Sabbath and why you observe the Sabbath - this is the Jewish Sabbath. And you quoted Rabbi Abraham Joshua Heschel, who described the Sabbath as a cathedral in time - a kind of sacred space of time in which one rests and contemplates and spends time with other people. Do you still observe the Sabbath?

SHULEVITZ: Oh yeah, we do. And as I said at the time, I am not strictly Shomer Shabbat, which is the Hebrew term for, you know, following all the laws very strictly. I'm very - we're very un-strict about it, in fact. We have our own little interpretation of the rules. The strongest of which is that we do not use electronics. I feel that electronics have really taken over childhood and adulthood. And I feel a little, I feel driven and almost enslaved by my iPhone and my computer. And we turn all that stuff off. I used to, and I think I was still at the time of our last interview, not using the phone. But life is so complicated when you don't use the phone and everyone around you expects you to use the phone that I've sort of given in on that. So I do take the phone if I see that the call is coming from someone I really need to talk to. But yes, we do try to create that pause. And I'm so glad that my children just simply know and assume that they're not going to be able to turn anything on for 24 hours. It makes them much more aware of what the possibilities are outside the screen.

GROSS: I guess it's much better to start doing that at a really young age as opposed to taking it away from them after they've already gotten used to having constant access seven days a week.

SHULEVITZ: Yeah. It's harder. But, you know, it's best to sort of come up with this plan before you start raising your children. But people, you know, go on their own spiritual journey and arrive at decisions after their children are starting to grow up or grown up and, you know, they shouldn't shy away from the consequences of those decisions just because they're hard.

Another thing about - that we do on our Sabbath is we spend time with our fellow Sabbath community, members of our fellow Sabbath community, people who are also keeping some version of the Sabbath and going to synagogue and having meals together. And that's important too.

And that's one of the cases I make in my book, is that the Sabbath - the Christian Sabbath as well as the Jewish Sabbath, because I talk a lot about the Christian Sabbath - was a time in which community could gather across class lines, possibly without being, sort of, focused on their professional identity, and interact with each other. And it's important to make time for community.

GROSS: So you've written about religion and now your main topic is science. So any thoughts you'd like to leave us with about science and religion?

SHULEVITZ: I don't think that they're mutually exclusive. I think that the aspect of science I'm completely with right now is epigenetics, which I talked about, the science of gene expression. And the reason I'm obsessed with it is because that it's clear that these genes - these molecules that latch onto genes and turn them on and off - respond to the environment.

And what amazes me about that is that what we're discovering is that we're enormously malleable. We're really responsive to our environment, and not just to our environment in a physical sense but also in a psychological sense, in the sense that stress is one of the really big forces in epigenetic changes.

So the malleability of the human body, seems to me, an argument for creating a better community, a better society. And that's what I love about religion, is that it's a place where you can turn for ideas about the good society.

I recognize - as many people go around arguing - that religion can be used as a force for bad - as any set of ideas or ideology can be - but it can also be used as a source of ideas that drive us to the greater good. So I turn to science to tell us how to live, and I turn to religion to tell us how to live, and I follow neither of them slavishly.

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GROSS: OK. Judith Shulevitz, thank you so much for talking with us.

SHULEVITZ: Thank you, Terry.

GROSS: Judith Shulevitz writes about science for the New Republic. Her article, "The Grayest Generation," was published last month in the magazine. The National Book Critic Circle is giving this year's Lifetime Achievement award to the authors of "The Madwoman in the Attic: A Feminist Analysis of Victorian Literature." Coming up, our book critic Maureen Corrigan has an appreciation. This is FRESH AIR. Transcript provided by NPR, Copyright NPR.